Fuse plug



March 19, 1935. B. l.. Moss 1,994,895

` FUSE PLUG Filed March 2, 1932 Patented Mar. 19, 1935 UNITED STATESPATENT OFFICE 1 Claim.

'I'he invention relates to fuse plugs, and has as an object theprovision of a fuse plug provided with a plurality of fusible elementswhich may be successively brought into use.

Another object of the invention is to provide a multiple fuse plugadapted to carry in compact form a considerable number of fuse elementsfor successive use, and to provide convenient and simple means forselectively connecting said fuse elements between the terminals of theplug.

A further object of this inventionfis to provide a multiple fuse plughaving a rotating switch member for selectively connecting a series offuse elements between the terminals of theplug.

A still further object of this invention is to provide a multiple fuseplug having novel and improved means adapted to indicate if the fuseelement in use is intact.

A still further object of the invention is to provide a multiple fuseplug having a minimum number of parts, which may be readily assembledand manufactured'at a cost convenient for low cost production, whichwill be simple in construction and operation, and which will be highlyefficient for carrying out the purposes for which it is designed.

With the foregoing and other objects in view, which will appear as thedescription proceeds, the invention consists in certain novel andimproved features of construction, arrangement and combination of partshereinafter `more fully described, illustrated in the accompanyingdrawing, and particularly pointed out in the appended claim, it beingunderstood that various changes in the form and minor details ofconstruction may be made without departing from the spirit orsacrificing any of the advantages of the invention.

For the purpose of facilitating an understanding of my invention, I haveillustratedr in the accompanying drawing a preferred embodiment thereof,from an inspection of which, when considered in'connection with thefollowing description, my invention, its mode of construction, assemblyand operation and many of its advantages should be readily understoodand appreciated.

Referring to the drawing, in which similar characters of reference areemployed to indicate corresponding or similar parts throughout theseveral figures of the drawing:-

Figure 1 is a central sectional view of a multiple fuse plug whichembodies the invention;

Figure 2 is a transverse sectional view through the plug taken on line 22 of Figure 1; and

Figure 3 is an exterior view of the capped end of the-plug.

Referring to the drawing more specically by characters of reference,wherein I have shown a preferred form of the invention, the referencecharacter l0 designates generally the body portion or casing of the fuseplug, said body portion or casing 10 being formed from electricalinsulation, such as glass, porcelain, or the equivalent. for thepurpose. A portion of the outer wall of the casing 10 has a. metal shellor sleeve 11 closely tted thereto, and surrounding said metal sleeve l1is a second metallic sleeve 12 which is threaded so that the fuse plugmay be received in threaded relation in the usual socket in the mannerkcommon to devices of this character, the shell 12 making electricalcontact with the wall of the socket.

.Mounted in 'longitudinal passages 13, there are shown the fusibleelements 14, one end of which is secured in electrical contact with thesleeve 11, as by soldering, or in some other suitable'and wellknownmanner. The upper end of each fusible element 14 is bent at rightangles to form the horizontally disposed portion 15, the freeend ofwhich is again bent downwardly at right angles to form the dependingportion 16. The depending portion 16 is adapted to be received and heldagainst the side wall of the chamber 17 provided in the upper portion ofthe insulated casing 10, the horizontally disposed portions 15 of eachof the fuse elements being disposed soas to rest on a portion of thecasing 10, as shown in Figure 1 of the drawing. These horizontalportions 15 of the fuse elements are provided with a reduced portion 18which determines the capacity of the element. The chamber 17 provided inthe upper portion of the casing 10 has the inner Wall thereof providedwith the cam surfaces 19 as shown in Figure 2 of the drawing, which camsurfaces are for the purpose to be presently more fully described.

A central contact for the plug is provided by the end of a rod 20,revolubly mounted in the casing 10, the casing 10 being retained on saidrod by means of the enlarged head 21 and washer 22. The head 21 isadapted to engage the central contact (not shown) of the usual socket inthe well known manner.

To provide electrical connection between the rod 20 and the fusibleelements 14, there is shown an arcuate contact member 23, which isformed integral with an arm 24, which arm is bent around and rigidlysecured by means of the rivets 25, or in some other Vsuitable and wellknown manner, to a attened portion of the rod 20, as shown in Figure 2of the drawing. The assembly between the arcuate contact 23 and the rod20 is arranged so as to cause the former to rotate with the rod.

The upper end of the rod 20 extends above the casing 10 and has rigidlysecured thereon in any suitable .and well known manner, such for exampleby press nt or the like, the actuating knob 26, whichknob is formed ofany suitable insulating material, such as glass, porcelain, or the like,said knob having formed integral therewith the projection 27 for visiblyindicating the fuse element which is in use.

A cap member 28 is provided with a central aperture 29, through whichthe nger piece or knob 26 is adapted to extend, said cap element beingrigidly secured to the casing 10 by having the lower portion thereofcrimped, as shown at 30 in Figure 1 of the drawing. Disposed between theupper surface of the casing l0 and the inner surface of the cap member28 is a disc 31, which hasv an aperture 32,.,through which the knob orlinger piece 26 is adapted to pass. The disc 31 vis made of translucentmica or the equivalent, for the purpose. The cap member 28 is providedwith theropenings 33 in the upper surface thereof, through whichopenings portions of the mica sheet 31 may be readily observed. rIhus,in'this instance, four fuse elements 14 are provided and the cap member28 is provided with the openings 33, each one of said openings beingdisposed directly above the horizontally disposed portion 15'of each ofsaid fuse elements.

When the device has been completely assembled and the fuse plug is to beinserted in the usual socket, the finger piece or knob 26 is manipulatedso as to bring the contact 23 into engagement with one of the fuseelements lli, at which time the indicating member 27 Ywill be disposedopposite the opening 33 for indicating the fuse element which is then inuse. When this element fails, the rod 20 is rotated to the right untilthe indicator 27 is brought to position opposite the next opening 33,whereupon the next fuse element will be engaged by the arcuate contact23.

Thereafter, each time a fuse element burns out, the rod 20 is rotated tobring the next fuse element into engagement with the contact 23 untilall of the elements have been used. A new plug may then be inserted inthe socket. The provision of the camrned surfaces 19 on the Yinner wallof the chamber 17 is such as to permit rotation of the contact element23 in a clockwise direction only.

The above construction is particularly advantageous,` as when one of thefuse elements burns out, the gas evolved from the fuse portion willcause a discoloration of the under surface of the disc 31 below theopening 33, indicating to the observer that the fuse element disposeddirectly below said opening has burned out and that the rod 20 must berotated to bring the contact 23 into registry with the succeeding fuseelement.

Because of the compactness of the device, the multiple plug of theinvention may be freely substituted in any location where the singleform of plug is now in use, thus obviating a serious objection toV otherforms of multiple fuse plug of which Iam aware. The describedconstruction is one that ymay be quickly assembled and canbemanufactured at a comparatively low cost. Soldering of the fuseelements 14 to the shell 11 is readily accomplished, since the innerwall of the shell will form little receptacles for the solder, inconjunction with the walls of the channels 13. Also the utilization ofthe rotatable rod to retain the contact arm 23 in engagement with thedesired fuse element is a feature that expedites assembly. A desirablecompactness results from the arrangement of the fuse elements in a cir-rcular series at the center of which the rod 20 is located.

1t is believed that my invention, its mode of construction and assemblyand many of its advantages should bereadily understood from theforegoing without further description, and should Valso be manifest thatwhile a preferred embodiment of the invention has been shown and described for illustrative purposes, the structural details are,nevertheless, capable of wide variation within the purview of myinventionas dened in the appended'claim.

rWhat I claim and desire to secure by Letters Patent of the UnitedStates isz- A multiple fuse plug comprising, in combination, a body ofinsulating material having a plurality or" unconnected longitudinalpassages concentrically arranged,` a metal shell mounted on the surfaceof said body, a fusible element mounted in each of said passages andarranged in electrical contacting engagement with said shell, acentrally disposed chamber formed in the upper portion of said body, anupstanding wall separating said passages from said centrally disposedchamber, the free ends of said fusible'elements being bent over theupper edge of said wall and extend into the said chamber and arranged incontacting engagement with the inner surface of said wall, a rodextending through said body and journaled for rotation therein, a springcon- `tact rigidly secured to said rod and ydisposed in said chamber,whereby said spring Contact will successively engage said fusibleelements upon the rotation of the rod, a translucent member mounted inthe upper portion of said body, and an apertured cap closing the upperportion of said body and being disposed directly above said translucentmember, the apertures in said cap Y being arranged so as to lie directlyabove said longitudinal passages whereby the translucent member will beeiective for indicating by its discoloration the positions of fuseelements which have'burned out.

BENJAMIN L. MOSS.

